The present invention, in some embodiments thereof, relates to optics and, more particularly, but not exclusively, to a system and method for controlling light.
A light wavefront can be shaped by optical components, such as lenses and prisms, as well as diffractive elements, such as gratings and holograms, relying on gradual phase changes accumulated along the optical path.
Known in the art is the use of flat optical components which exploit the wave diffraction phenomenon and create engineered diffractive optical elements made out of amplitude and phase plates. Recently there were some demonstrations of control and diversion of light field by using metasurfaces.
Aieta, et al., Nano Letters 12, 4932 (2012), apply optical phase discontinuities to the design of a phased array of ultrathin subwavelength-spaced optical antennas. V-shaped nanoantennas introduce a radial distribution of phase discontinuities, thereby generating respectively spherical wavefronts and non-diffracting Bessel beams at telecom wavelengths.
Chen et al., Nature Communications 3, 1198 (2012), teach a dual-polarity flat lens based on helicity-dependent phase discontinuities for circularly polarized light. By controlling the helicity of the input light, the positive and negative polarities are interchangeable in one identical flat lens. Helicity controllable real and virtual focal planes, as well as magnified and demagnified imaging, are observed on the same plasmonic lens at visible and near-infrared wavelengths.
Fu et al., Optics Express 18, 3438 (2010), teach a plasmonic lens with metallic chirped circular nanoslits corrugated on Au film supported on quartz substrate for the purpose of super-focusing. An improved focusing performance in comparison to that of the non-chirped lens is reported.
Ellenbogen et al., Nano Letters 12, 1026 (2012), teach nonlinear generation of Airy beams using wave mixing processes, which occur in asymmetric nonlinear photonic crystals.